Fuel injection cold start and evaporative control method and apparatus for carrying out same

ABSTRACT

As cold start is initied in a spark-ignition internal combustion, fuel injection engine, lower molecular weight constituents of a full-range gasoline are selectively eluted by an elution system including an adsorbent bed of adsorbent material, for example, silica gel. The adsorbent bed forms an elution zone within a cannister assembly in fluid contact with the full-range gasoline. The adsorbent material-usually in pelletized form-is preferably housed within a tubular means being positioned within a much larger shell housing in fluid contact with a valve and conduit network. Entry of the gasoline is initiated by the valve and conduit network under control of a fuel injection control circuit. A vapor emission control system can also be housed within the cannister assembly and undergo selective operation to prevent escape of vapor emissions originating from within the gasoline tank.

United States Patent Csicsery FUEL INJECTION COLD START AND EVAPORATIVECONTROL METHOD AND APPARATUS FOR CARRYING OUT SAME [75] Inventor:Sigmund M. Csicsery, Lafaeytte, Calif.

[73] Assignee: Chevron Research Company, San

Francisco, Calif.

[22] Filed: Oct.'4, 1972 [21] Appl. No.: 295,040

[52] US. Cl 123/3, 123/127, 123/180 R,

123/180 A [51] Int. Cl. F02m 27/02 [58] Field of Search 123/32 EA, 179L, 180 R, 123/180 A, 127, 3, 133, 135

[56] References Cited UNITED STATES PATENTS 1,490,192 4/1924 Anderson123/127 3,221,724 12/1965 Wentworth 123/136 3,494,340 2/1970 Weber et al123/139 AW X 3,635,200 l/l972 Rundell et al. 123/3 3,673,989 7/1972 Aonoet al 123/32 EA 3,688,755 9/1972 G'rayson et al 123/3 PrimaryExaminer-Charles J. Myhre Assistant Examiner--William Rutledge, Jr.Attorney, Agent, or FirmR. L. Freeland, Jr.; H. D. Messner ABSTRACT Ascold start is initied in a spark-ignition internal combustion, fuelinjection engine, lower molecular weight constituents of a full-rangegasoline are selectively eluted by an elution system including anadsorbent bed of adsorbent material, for example, silica gel. Theadsorbent bed forms an elution zone within a cannister assembly in fluidcontact with the full-range gasoline. The adsorbent material-usually inpelletized form-is preferably housed within a tubular means beingpositioned within a much larger shell housing in fluid contact with avalve and conduit network. Entry of the gasoline is initiated by thevalve and conduit network under control of a fuel injection controlcircuit. A vapor emission control system can also be housed within thecannister assembly and undergo selective operation to prevent escape ofvapor emissions originating from within the gasoline tank.

8 Claims, 9 Drawing Figures VAPOR CONTROL. VALVE RELAY FUEL INJECTCONTROL CIRCUIT was.

srmaur PAIEMEUBU 11914 FUEL INJECTION COLD START AND EVAPORATIVE CONTROLMETHOD AND APPARATUS FOR CARRYING OUT SAME RELATED APPLICATIONSApplications filed simultaneously with the subject disclosure which areassigned to a common assignee and containing common subject matter butclaiming distinct inventions, include:

Single-stage Cold Start and Evaporative Control Method and Apparatus forCarrying Out Same, Sigmund M. Csicsery, Ser. No. 295,028; Two-Stage ColdStart and Evaporative Control System and Apparatus for Carrying OutSame, Sigmund M. Csicsery and Bernard F. Mulaskey, Ser. No. 295,029;Cold Start Method and Apparatus for Carrying Out Same, John F. Senger,Ser. No. 295,041; Two-Stage Fuel-Injection Cold Start Method andApparatus for Carrying Out Same, Sigmund M. Csicsery and Bernard F.Mulaskey Ser. No. 295,030, now abandoned.

The present invention relates to cold starting and evaporative emissioncontrol of a spark-ignition, fuel injection internal combustion engineand has for an object of the provision of a simple and effective coldstart and evaporative control system for use in such engine i. forselectively eluting from a full range fuel flowing to the engine onlythe lower molecular weight constituents at cold start so as to allowquick starting of the engine without excessive amounts of unburnedhydrocarbons appearing at the exhaust as well as ii. for adsorbingevaporative emissions from the gasoline tank when the engine is notoperating.

Higher molecular weight-constituents adsorbed during cold start and/orlight, evaporative emissions adsorbed during the disabled cycle of theengine are purged from the system only after the engine has been warmedand the full range fuel utilized.

During cold start of spark-ignition, fuel injection internal combustionengines, the fuel-air ratio is generated by the air-fuel intake system,say a conventional fuel injection system. At cold start, the air-fuelratio can be varied (enriched) to assure adequate amounts of lowermolecular weight constituents of the fuel at the intake manifold. Byoperation of a pluality of interrelated well-known parts, the lowermolecular weight constituents become more easily vaporized to formcombustible vapor-fuel/ air ratios to allow starting of the engine evenat low operating temperatures. However, since remaining higher molecularweight constitutents are not oxidized even if the start is rapid, suchremaining constituents contribute to the formation of unburnedhydrocarbons at the exhaust.

Although a more volatile fuel having a lower boiling point, would permitfaster starts and warmup and reduce exhaust pollutants, includingunburned hydrocarbons and carbon monoxide emissions, experience showsthat full range engine performance using the more volatile fuel would beadversely affected. In this regard, fuel consumption would be greatlyincreased over all ranges of driveability.

In accordance with the present invention, rather than use a morevolatile fuel under a multiplicity of operating conditions of asnark-ignition, fuel injection internal combustion engine (particularlyduring cold start), lower molecular weight constituents of a full-rangegasoline are selectively eluted as cold start is initiated by thedriver. The elution system includes an adsorbent bed of adsorbentmaterial, preferably of the polar type,

for example, silica gel forming an elution zone within a cannisterassembly in fluid contact with the full range gasoline. The adsorbentmaterial-usually in pelletized form-is preferably housed within atubularmeans disposed within the cannister assembly, the tubular meansbeing positioned within a much larger shell housing in fluid contactwith a valve and conduit network. Entry of the gasoline is initiated bythe valve and conduit network under control of a fuel injection controlcircuit.

Construction of the cannister assembly can vary. Preferably thearrangement resembles that provided for a shell-and-tube heat exchangerwhereby tube-side gasoline-during cold startpasses through the tubularmeans packed with the adsorbent material (single pass percolation).Selective retardation of the higher molecular weight compounds vis-a-visthe lower components occurs so that, during start up, only the latterconstituents pass to each of a series of electromagnetic injectors in apreselected time sequence, and thence are mixed with air in apreselected air-fuel ratio for later consumption within the combustionchambers of the engine. Since the starting cycle of an internalcombustion engine is quite short, say from 1 to 15 seconds and theresidence time for the heavier compounds within the elution zone is oneto two orders longer, say from I to 3 minutes, the latter compoundsremain selectively adsorbed with the elution zone.

Preferably, but not necessarily, the present invention has additionalutility in preventing evaporative emissions originating within thegasoline tank from escaping into the atmosphere. In this aspect of theinvention, the escape of large amounts of hydrocarbon fumes and vaporsinto the atmosphere from a spark-ignition internal fuel injection enginein an inoperative state, is acknowledged as being a seriousenvironmental problem, especially within large cities. Governmentalbodies are attempting to satisfy emission regulation in cooperation withindustry, for example, California Motor Vehicle Pollution Control Boardhas proposed the following standards for control of evaporativeemissions from gas tanks: 6 grams per day under standard operatingconditions. In this regard, the present invention can be selectively,but not necessarily, operative during such time periods to adsorb suchevaporative emissions and prevent their escape into the atmosphere byarranging the cannister assembly so as to provide an annular spacebetween the tubular means and the shell housing. Into the annular spacecan be inserted an adsorbent material, preferably of the nonpolar type,which form an adsorptive capture zone for use in preventing escape ofevaporative emissions into the atmosphere when the engine is in aninoperative state.

The associated valve and conduit network and the fuel injection controlcircuit can place both the elution and capture zones of the cannisterassembly in fluid contact with other relevant fuel system components asrequired; for example, after the engine has started and warmed up boththe elution and capture zones can be purged of adsorbed constituents(adsorbates) by passing shell-side gases (either full or partial engineair or manifold exhaust gases) through these zones. Thus, not only isthe present invention able to rapidly elute lower molecular weight fuelconstituents at cold startup, but the other adsorbed fuel components canbe automatically desorbed without formation of excessive amounts ofpollutants at the exhaust.

Further objects, features and attributes of the present invention willbecome apparent from a detailed description of several embodiments to betaken in conjunction with the following drawings in which:

DESCRIPTION OF THE FIGURES FIG. 1 is a schematic view of a portion of anengine fuel system incorporating the present invention illustrating atypical fuel injection system and air cleaner assembly interconnectedbetween a cold start evaporative emission system of the presentinvention, said cold start evaporative control emission system includinga cannister assembly housed within the air intake line of the aircleaner assembly under regulation of a valve and conduit networkcontrolled by a fuel injection control circuit;

FIG. 2 is a partial cutaway of the cannister assembly of FIG. 1;

FIG. 3 is a sectional view taken along line 33 of the cannister assemblyof FIG. 2;

FIG. 4 is a schematic view of another embodiment of the presentinvention illustrating, in association with a typical fuel injectionsystem and air cleaner assembly, a cannister assembly mounted by meansof a platform attached to the firewall of the engine compartment;

FIG. 5 is a plan view of the cannister assembly and air cleaner assemblyof FIG. 4;

FIG. 6 is a circuit diagram of the fuel injection control circuit ofFIG. 1 illustrating how the injection cycle and cold start cycle areinterrelated;

FIG. 7 is a partially schematic view illustrating an alternativeembodiment by which air can be heated in an elevated temperature tobetter desorb the cannister assembly of FIGS. 1 and 4;

FIG. 8 is a fragmentary view of the valve and conduit network of FIG. 1illustrating the position of the valve network after cold start has beenachieved and the engine is at running temperature so that the cannisterassembly can be desorbed;

FIG. 9 is yet another fragmentary view of the valve and conduit networkwhen the engine is in an inoperative state.

Referring now to FIG. 1, there is illustrated a combustion chamber 9 ofa spark-ignition internal combustion engine connected to an engine fuelsystem 10 through an engine intake manifold 11. Fuel system 10 of thepresent invention includes an air intake assembly 13, a fuel intakesystem 14 and a fuel injection control circuit 15.

To form a combustible air-fuel mixture, air enters by way of air intakeassembly 13 say by way of air inlet line 13a, and is filtered at an airfilter interior of an air filter housing 130, before entry into intakemanifold 11. Manifold ll includes air temperature gauge 16, butterflyvalve 17, vacuum sensor 18, and a mixing chamber 19 connected tocombustion chamber 9 through intake valve 12. Also connected to themixing chamber 19 adjacent to intake valve 12 is a fuel injection valve20. Fuel injector valve 20 allows a metered quantity of gasoline to bemixed with air passing into mixing chamber 19 so as to provide aresulting fuel-air mixture passing through intake valve 12 into thecombustion chamber 9 where combustion occurs. A segment of fuel intakesystem 14 includes a gas tank 21 containing a reservoir of full-rangefuel (i.e. a full-boiling gasoline), a filter 22, a pump 23 andapressure regulator 24. Pump 23 is driven through a motor 25 connected tofuel injector control circuit 15 to pump fuel by way of cold start inletvalve 26a of conduit and valve network 26 and thence to a cannisterassembly 28, mounted adjacent to the air intake assembly 13 say withinair inlet line 13a.

Valve and conduit network 26 is seen to also include a cold start exitvalve 26b, controlled mechanically by cold start relay means 30 throughtransducer 31. A second relay means 32 is seen to control operation ofevaporative emissions control valve 26c of valve and conduit network 26through mechanical transducer 33. Transducers 31 and 33 convertrectilinear-travel of the relay means 30 and 32 to rotational motion.However, note that instead of being regulated by control circuit 15, thesecond relay means 32 is seen to be controlled by ignitionswitch 35connected to battery 34. Thus, the activity of ignition switch 35 isdirectly reflected in operation of theevaporation control valve 26cconnected to the relay means 32, in the manner explained in more detailbelow.

Fuel injection control circuit 15 is also seen to be connectable tobattery 34 as ignition switch 35 is closed, the battery 34 being itselfconnected to a generator (not shown) in conventional manner, say by wayof a regulator. When ignition switch 35 is closed, the control circuit15 becomes operational. Input information by way of the followingtransducers is received: air temperature gauge 16, vacuum sensor 18,engine temperature indicator 36, travel sensor 37, RPM and shaft angleindicator 38. From this data the circuit 15 commands relevant parts ofthe fuel system 10 using a selected binary code of current pulses(ONE-ZERO), to adapt fuel requirements at the injector 20 to changingconditions of operations. E. g., in this regard, the period time of, saythe ONE state can be used to indicated the energization period of eachof a series of injectors 20, while the ZERO state to indicate theinactivity period of relevant elements of the system.

In more detail, the start of each pulse at a particular injector, sayinjector number 2 (of 8) is synchronized (timed) to occur when aparticular shaft angle indication is provided by shaft angle-RPMindicator 38. After a pulse has been correctly initiated, its period(pulse width) is basically a function of the manifold pressure (engineload) asprovided by vacuum sensor 18. Corrections by which pulse widthis stretched or diminished, are a function of data supplied by theremaining sensors, i.e., air intake temperature, engine temperaturethrottle valve movement and engine speed.

Prior art electronic fuel injection systems have had difficulty inproviding fuel requirement at cold start even when using a separatestart valve attached to intake manifold. The present invention providesa cold start function through selective elution of a fuel rangegasoline, percolating through cannister assembly 28 for providing light,low molecular weight liquid components at the injector valves 20 formixing with air to form the cold start fuel-air mixture. A cold engineis one which, in attempting to assume an ambient air'temperature, hascooled to a temperature below a selected level. This level isempirically determined and is the temperature below which difficulty ofstarting isincreased beyond the usual capability of fuel injectioncontrol circuit 15.

In accordance with the present invention, lower temperature limits forstarting of an internal combustion engine, are extended using onlylight, low molecular weight liquid components of a full-range fuel,i.e., a full-boiling gasoline, at startup. Note that although afull-range fuel is conveyed from gas tank 21 through pump 23 into valveand conduit network 26, and thence to cannister assembly 28 onlylightweight constituents are eluted from cannister assembly 28 andcarried to the injector valves 20 for mixing with air. The principalreason for such operation: selective retardation of heavier componentshas occurred during the initial 1-to-3 minutes of the starting cycle ofthe internal combustion engine due to the operational characteristics ofthe cannister assembly 28. Since the nature of the assembly 28 is basedon functional characteristics of adsorbent materials, in general, and ofpolar type adsorbent materials, in particular, a brief discussion ofadsorption systems is believed to be in order and is presented belowwith reference to FIG. 2.

Cannister assembly 28 includes an interior tubular means 41, locatedwithin a much larger shell housing 42. In essence, the tubular means 41forms a column of a solution adsorption, frontal analysis chromatographas classified in accordance with Kirk-Othmer Encyclopedia of ChemicalTechnology, 2nd Ed., Volume 5, page 418. In accordance with Kirk-Othmerop. cit., such classification is essentially based on the nature of themobile phase of the system percolating through an adsorbent material. Inthe case at hand, full-boiling gasoline enters by way of inlet conduit43 and percolates through adsorbent material 44 packed within thetubular means 41. Note at the outlet conduit 46, the order of elution isa function of the order of polarity of the constituents of the fullrange gasoline since the individual molecules of the heavier molecularweight constituents within the tubular means 41 shuffle at a slower ratebetween the mobile and stationary phases than do the lighterconstituents. Thus, within elution zone 40, coextensive with butinterior of tubular means 41, separation is believed to occur, interalia, because of polarity, nonpolarity characteristics of theconstituents whereby different relative velocities are imparted to theindividual molecules of the groupings. The least strongly adsorbed lowmolecular weight components elute as a group at the outlet conduit 46first, followed by a second grouping containing say both light and heavyconstituents and so forth until all constituents have appeared.

Residence time of the light components within the elution zone 40 is afunction of many factors including the length of the tubular conduitmeans 41 as well as the pressure drop during percolation through theadsorbent material 44. However, the residence time of the heaviercomponents is much longer in duration, in a range of 1-3 minutes.However, care ought be exercised in this regard. The flow rate of themobile phase must be slow enough to allow maximum transfer of themolecules of the heavier constituents into and from the stationary andmobile phases. Since selective retardation of the heavier constituentsdue to relative polarnonpolar interaction between the heavier componentsversus the adsorptive material 44, is quite long, say 1-3 minutes, whilethe typical starting cycle of a modern engine can be quite short, sayfrom 1 second up to seconds (except when problems of starting occurs),the heavier constituents remain adsorbed within the tubular means 41after the engine has started. This proposition assumes, of course, thatthe adsorbent material 44 constituting the elution zone 40 is of acompatible polar classification.

As previously mentioned, competition for the heavier molecular weightgroupings of the full-range fuel is believed to be dependent, more orless, on its selective polar interaction with the adsorptive material44. The magnitude of interaction (between the material 44 and theheavier constituents of the full-range fuel) is believed to be directlyrelated to the degree of polarity of the adsorptive material. Inaccordance with the present invention, then, adsorptive material 44 ispreferably polar, and preferably selected from the followingnonexclusive listing of popular polar adsorptive materials, with silicagel being somewhat preferred.

Polar Adsorptive Materials Remarks Ion-exchange only Commonly Used inLiquid-liquid Partition Chromatography Adsorbent material 44 can beformulated in a convenient form for use within the cannister assembly28. For example, the elution zone 40 can be formed of adsorbent materialin granular, pelletized or powdered form. Preparation is straightforward: the adsorbent material should be calcined, acid and basewashed, neutralized, and size graded prior to insertion within tubularmeans 41, say pelletized lines set forth in Kirk- Othmer, op. cit.,Volume 1, page 460. Since, as previously mentioned, the flow rate of thefull range gasoline within the elution zone must be slow enough to allowmaximum transfer of the molecules of the heavier compounds into and fromthe stationery and mobile phases, the size of the adsorbent material 44should be such as to minimize the pressure drop across a cannisterassembly 28 without adversely affecting its ability to adsorb theheavier constituents. In this regard, an elution zone 40 having about a1-liter capacity filled with activated alumina of 8 by 14 mesh has beenfound to adsorb from 200-300 ml. of aromatic constituents while yieldingabout 400 to 500 ml. of lightweight constituents in the first initialminutes of the cold starting operation. In addition to activatedalumina, it has been found that polar gels, such as silica gel, titaniagel, zirconia gel, and alumina gel, as well as Fullers earth, bentonite,diatomaceous earth, forisil, attuplugus, and any other polar adsorptivematerials are also useful in carrying out the present invention.However, in some cases, non-polar materials may also be used within theelution zone as a substitue for the above-identified polar materialswithout undue loss in effectiveness. Non-polar materials listedhereinafter are appropriate in this regard.

Construction of the cannister assembly 29 varies with the type ofmounting required to attach the conduit and valve network 26 adjacent toair intake system 13. In FIG. 2, cannister assembly 28 is seen to bemounted within the intake air line 13a of the air intake system 13. Theoverall diameter of the cannister assembly 28 thus must be minimum so asto allow sufficient air to bypass through intake manifold 11 to mixingchamber 19. To accomodate the required volume of adsorbent materialconstituting the elution zone 40 the tubular means 41 may have to becorrespondingly ultra-long. Support of the ultra-long tubular means 41can be brought about by welding radial supports 47 to the side wall ofair line 13a to which cold start conduits 43, 46, as well as evaporativeconduit 60 are attached. Support rings 51 are attached at respectiveends of the tubular means 41. Each ring 51 has a peripheral edge .incontact with the shell housing 42. Each ring 51 also in eludes a centralplug zone in plugging contact with the central tubular means 41 as wellas an intermediate zone 53 (See FIG. 3) including a series of ports 54in registry with an annular spacing existing between tubular means 41and the shell housing '42 wherein adsorbent material 55 is supported.Adsorbent material 55 .located in the aforementioned annular spaceconstitutes a vapor adsorption zone, generally indicated at 56(adsorption capture zone). In this aspect of the invention, deactivationof ignition switch 35 (of FIG. 1) deactivates relay means 32 causingrotation of the vapor control valve 260 to the position shown in detailin FIG. 9. The gas tank 21 is thus placed in fluid contact with thevapor adsorption zone 56. Note that at the shell side exterior of thecentral tubular means 41, i.e., within adsorption zone 56, theatmosphere is permitted to enter and leave at will. During cold start,since the shell-side air is at about the same temperature as the fluidinterior of the tubular means 41, little heat is transferred between thetwo fluids.

In FIG. 4, the support of the cannister assembly 28 differs markedlyfrom that of FIG. 1. The cannister assembly 28 of FIG. 4 is seen to bemounted by shell housing 42 to a platform 57 which in turn is attachedto a firewall (not shown) of an engine compartment. Additional spaceafforded by the platform 57 allows for a more complex constructionaldesign of the cannister assembly 28. Instead of constructing tubularmeans 41 ofa single tube as depicted in FIG. 1, a series of uprighttubular means 41 can'be provided to carry the gasoline entering inletchamber 59 along a series of sinusoidal passages through the interior ofthe cannister assembly 28, such passageways-resembling those provided ina conventional tube-and-shell heat exchanger. The series of passes madeby the gasoline are indicated by solid arrows 60, while clotted arrows61 indicate the directions of the gas phase flow.

In the depicted arrangement, tube-side gasoline is conveyed during coldstarting through the tubular members 41' between the inlet and exhaustchambers 59 and 62 respectively (multipass percolation) throughadsorbent material 44' packed within the tubular members 41. Due toincreased total length of the tubular means 41, the resulting, compositeelution zone 40' is likewise greatly enlarged over that depicted in FIG.2, assuming the absolute length of the cannister assembly of FIG. 4remains the same. Not only does the effluent at the exhaust chamber 62consist essentially of light, low molecular weight constituents duringthe cold start cycle, as previously explained, but also the heaviercompounds remain adsorbed within adsorbent material 44- until long afterthe engine has warmed up. That is to say, because the heavier compoundsare retarded during percolation through the elution zone 40 for a longertime than required to usually start the engine, the effluent within theintake manifold per each starting cycle of the internal combustionengine is limited essentially to lightweight constituents.

Further constructural differences between the embodiments depicted inFIG. 1 and FIGS. 4 and 5 are readily apparent. For example, in FIG. 5,the shell housing 42' is seen to be rectangular in cross-section wherebythe assembly forms a parallelpipedon. Also, the housing 42' is also seento include end walls 63. Each end wall 63 includes a series of ports 64to allow selective entry (in direction of arrows 61) of hot, exhaustgases into an adsorptive vapor capture zone generally indicated at 56exterior of tubular members means 41', but interior of shell housing42'. Within the vapor capture zone 56', adsorbent material 55' issupported. One of the end wall 63 is also seen to attach by way offasteners to the air cleaner housing 130. Such attachment is orientedsuch that its ports 64 are in registry with aperature 13b of the aircleaner housing 13c. The other of the end, the end wall 63 is seen to beconnected to a conduit 65 having a remote end (not shown) connected to asource of exhaust gases, say the exhaust manifold of the engine.

Of course, tubular member means 41' need not be discontinuous so as torequire the use of intermediate chamber 66 (FIG. 4) to reverse the flowof the mobile phase. E.g., the tubular member means 41' can be U- shapedwith remote ends in fluid contact with inlet and exhaust chambers 58, 62respectively.

The operation of fuel injection control circuit 15 during cold start aswell as under normal driving conditions will now be described. Aspreviously mentioned, control injection control circuit 15 of FIG. 1receives various sensory inputs indicative of various engine operatingparameters after the circuit has been initialized. Of primary importanceat cold start, is a signal indication of engine temperature, such signalappearing at terminal 70 of the injection control circuit 15 of FIG. 6.Assume such signal at terminal 70 is below a selected set point level,so that relay means 30 (FIG. 1) is activated as the driver closesignition switch 35. The inlet and exhaust cold start valves 26a and261;, as well as evaporative control valve 26c, are reoriented from thepositions shown in FIG. 9 to those positions shown in FIG. 1. As theengine turns over, the pump 23 conveys full-range fuel through inletstart valve 26a to the cannister assembly 28. Within the cannisterassembly 28, the fullrange fuel percolates through the elution zoneculminating in the elution of low molecular weight components at each ofa series of injector valve 20. Heavier components of the full-range fuelremainadsorbed. From the injector valve 20, a metered amount of thelightweight components is conveyed into the mixing chamber 19 where thefuel and air are properly mixed and then convey for consumption withinthe combustion chambers of the engine. After selected rise in the enginetemperature, as indicated at terminal 70 of FIG. 6 relay means 30becomes deactivated, resulting in the cold start inlet and exhaustvalves 26a and 26b returning to relaxed positions as shown in FIG. 8.

After cold start exhaust and inlet valves 26a and 26b return to relaxedpositions depicted in FIG. 8, the fuel intake system switches over tofull utilization of the full-range gasoline. That is to say, fuelconveyed from pump 23 of FIG. 1 passes to inlet cold start valve 26a viaconduit 67a and thence from the valve 26a through U-shaped conduit 67band exhaust cold start valve 26b into the ejector valve 20 as a functionof control signals provided in fuel injection control circuit 15.

FIG. 6 illustrates the operation of fuel injection control circuit indetail. As indicated, the control circuit 15 is energized by a voltagesupply designated as B+, as noted. In the application of this system toan automobile, the voltage supply B+ can be a battery and/or a batterycharging system and additionally can provide a polarity readily reversedfrom that illustrated.

As explained previously, the control circuit 15 through designatedcircuit elements receives the following sensory inputs indicative ofengine operating parameters.

rent source, and current is passed through thyristors 86 to coil 87 ofone of a series of injector systems 69.

It should be apparent that at each injector coil 87, selection iscontrolled through coordination of angular postiion of the shaft of theengine as provided by transducer 38. In that way, synchronization of thetime of appearances of the control pulses provided by the pulsegenerator at the individual terminal 711) with the time of energizationof the multivibrator circuit 72.

After the transistor 85 conducts. transistor 80 is rapidly triggeredinto conduction as voltage at its base 80b (as determined by theadjacent RC network) decays to the value needed for the multivibratorcircuit to relax. As a result, transistor 75 is biased off, but it isquickly returned to a conducting state as the transistor 80 is biasedoff. To return the transistor 75 to a conducting state, it should beapparent that as conduction of transistor 80 occurs it acts incooperation with the voltage supply and adjacent resistors 88 and 89 asa current source to provide a base current to transistor 75 and SignalSource Parameter Operational Circuitry (FIG. I (FIG Manifold pressureEngine temperature Parameters Acceleration Engine Speed Air TemperatureShaft Angle Speed circuit 97 Engine temperature circuit 95 Accelerationcircuit 96 Air Temperature Circuit 98 In essence, the control circuit 15generates a plurality of control pulses, the width of which is linearlyvariable with a fundamental parameter, namely, the manifold pressure ofthe engine, as well as being capable of being stretched or diminished byremaining engine parameters. In order to initiate operations, as thedriver closes the ignition switch 35, a pulse generator (not shown) isenergized. The pulse generator (not shown) is connected to the inputterminal 71a of multivibrator cir cuit 72 via shaft angle transducer 38.In that way, the pulse generator is operative as a function of shaftangle so as to synchronize operation of the bistable multivibratorcircuit 72 with angular position of the shaft of the engine. To providesimilar synchronizing operations relative to particular injectorvalve20, the pulse generator also provides (via transducer 38) a pulse signalat input terminal 71b of injection valve circuit 69.

As shown in detail in FIG. 6, multivibrator circuit 72 includes acoupling capacitor 73 in series with base 74 of transistor 75 via diode76 and resistor 77. Shunting the coupling capacitor 73 is a second diode78 (through which the capacitor 73 can be discharged) and a resistor 79.

A start pulse received at base 74 of transistor 75 from the pulsegenerator, will trigger the multivibrator circuit into its unstablestate, i.e., transistor 75 into a conducting state. Mating transistor 80of the multivibrator circuit is base connected to collector 75a of thetransistor 75 through a network comprising resistors 81 and 82 andcapacitor 83. As transistor 75 conducts, the transistor 80 is caused toassume a voltage below its conduction state. However, voltage atcollector 80a of the transistor 80 will rise toward the B+ value. andthat value will be communicated via resistors 84a and 84b to powertransistor 85. The power transistor 85 in conjunction with an adjacentresistor network acts as a curcauses the transistor to conduct. The rateof switching between the transistors 75 and is rapid enough that it doesnot affect operation of power transistor 85. Le, even though themultivibrator circuit is undergoing rapid switching of transducer 75 and80, the power transistor remains in a conducting state. However, themultivibrator circuit 72 can be made to relax to its stable state uponthe receipt of a negative pulse at the base 74 of transistor 75, suchnegative pulse being generated by a separate control circuit 90.

Control circuit is seen to include variable resistor 91, condenser 92and unijunction transistor 93 connected in parallel with base 74 of thetransistor 75. When the voltage on the emitter of unitransistor 93(provided via a RC network comprising resistors 91 and 94 and condenser92), is equal to the voltage at its base 930, the unitransistor 93 isenergized causing a negative pulse to appear at base 74 of thetransistor 75. The result: the multivibrator circuit 72 returns to astable state. Voltage at the emitter of the unitransistor 93 is seen tobe determined by the time constant of the aforementioned RC network,while the voltage appearing at base 93a is a function of compositevoltage generated from the following control circuits, (i) enginetemperature circuit 95, (ii) acceleration circuit 96, (iii) speedcircuit 97 and (iv) air temperature circuit 98.

Engine temperature circuit operates to increase pulse width as afunction of temperature, but the tem-' perature which causes circuit 95to become operative must be below a selected point level, as explainedbelow. Temperature circuit 95 is seen to include a voltage divider 99formed by resistors 100, 101 and transistor 102. Assume the transistor102 isconducting, i.e., resistor network 103, 104 and 105 at its base,connect to the voltage supply B+ as shown. As the transistor 102conducts, the change in voltage at the collector 102a is seen to be adirect indication of engine temperature.

In other words, the change in voltage of the collector 102a of thetransistor 102 is reflected by the voltage divider 99 which in turn isreflected by a change in voltage at base 93a of unitransistor 93.

To provide a selected set point level for operation of the temperaturecircuit 95, the resistors 103, 104 and 105 are chosen such that thetransistor 102 saturates at a given engine temperature providing abalanced condition at voltage divider 99.

Air temperature circuit 98 operates in a similar manner as the enginetemperature circuit 95. As indicated, a voltage divider 107 is formed byresistors 108 and 109 and transistor 110. As previously, voltage at thebase of the transistor 110 is controlled by base resistors 111, 112 and113 connected to the supply 13+. The air temperature is indicated by theinternal resistance of the transistor 110 as reflected in change incollector voltage.

Acceleration circuit 96 is seen to include capacitor 114, resistor 115and potentiometer 116 which operates in cooperation with a voltagedivider 117 comprising resistors 118, 119 and transistor 120. Arm 116aof the potentiometer 1 16 is seen to connect via transducer 1 16b to thebutterfly valve of the engine via accelerator pedal 121. Thus movementof the pedal 121 causing displacement of the wiper arm 116:: changes thebias voltage appearing at base 120a of the transistor 120. Assume thatthe transistor 120 has been driven into conduction, but the voltagedivider 117 formed therewith is unbalanced. Thus the change broughtabout by the movement of the arm 116a will cause a change in thecollector voltage at collector 120b as a function of pedal movement. Theoperation of the acceleration circuit 96 occurs during a variable timeperiod dependent upon the time constant of the resistors 115, 125, thepotentiometer 116 as well as capacitor 114.

Speed circuit 97 is for the purpose of correcting for a lag time of airflow into the engine. Aerodynamic effects lead to a decrease in the rateof air intake as a function of increasing engine speed. Circuit 97includes a potentiometer 122 having an arm 122a connected by atransducer 122b to a tachometer (not shown) operative when a set pointlevel is exceeded to change the voltage level at the base 93a ofunitransistor 93 in the manner previously described.

Now returning to the embodiment depicted in FIG. 1 under control of thefuel injection control circuit of FIG. 6, it is apparent that controlsare there shown which will allow usage of full or partial engine airwarmed to a high temperature for desorption purposes. It should also benoted that the embodiment of FIG. 4 contemplates utilization of gasesfrom the exhaust manifold to purge with the elution and vapor adsorptionzones of adsorbed constituents. Now in more detail, after the engine hasstarted and warmed, and utilization of the full range fuel viareorientation of cold start valves 26a and 26b to the positions shown inFIG. 8, is occurring, simultaneously therewith, the elution zone of thecannister assembly 28, as well as the vapor zone of gas tank 21, areplaced in fluid contact with the intake manifold 11. Le, the elutionzone of assembly 28 is connected to the intake manifold 11 via conduits46, 48 and 49 (connected by respective ports of the valve 25b of FIG.1), while the gas tank 21 is likewise connected to the manifold 11 viaconduits 68a, valve 26c and conduits 68b and 49. In that way, asdesorption of the heavier compounds occurs, say as warmed gases areconveyed in heat transfer contact with the elution zone and the heaviercompounds are swept into the intake manifold 11, there can be asimultaneous conveyance of evaporative emissions, if any, from the gastank 21 to the manifold 11. With the desorption of heavier compoundswithin the elution zone, it should also be pointed out that vaporscaptured within the adjacent absorptive capture zone of the cannisterassembly can likwise be purged. However, instead of the desorbedmaterials entering the manifold 11 below the air intake system, thecaptured evaporative emissions pass directly into air intake system 13and thence to the manifold 11.

Where the heavier compounds within the elution zone of the cannisterassembly 28 have relatively high,

44 and 55' of FIG. 4 can be renewed using the hot ex-' haust gases asthe purging agent. If the temperature of such exhaust gases range from700 F to about 800 F, only a relatively short desorption time isrequired. Temperatures of the adsorbent bed comprising the elution zonecan be a range from 400500 F with about 450 F being a satisfactoryoperating temperature.

Generally desorption time is quite short for such range setting, saybeing from about 21 2 minutes in duration. The resulting desorbedaromatic compounds then pass through the air intake system to thecombustion chambers where they are consumed.

While purging of evaporative emissions within the vapor adsorption zoneof the cannister assembly 28 occur in the manner described above. Itshould be noted that the captured adsorbates within the vapor capturezone are mostly light, low molecular weight constituents. Accordingly,the adsorbent material indicated at 55 in FIG. 2 and at 55' in FIG. 5should be nonpolar. In this regard, the following non-polar adsorbentmaterials are preferred in carrying out this aspect of the presentinvention.

Non-Polar Adsorbent Material Remarks Charcoal Charcoal blacks GraphiteResins and Plastics Organic only Paraffins Stibnite Sulfides Metalliconly Talc Even though the cannister assembly 28 of FIG. 4 is larger thanthat depicted in FIG. 2, it provides better heat transfercharacteristics during desorption of the elution and vapor adsorptionzones since the available heat transfer area (between the heattransferring me dia) is much larger. That is to say, the shell-side hotgases traveling through the cannister assembly 28 of FIG. 4 is in heattransfer contact with a multiplicity of the tubular member means, notjust a single tubular means as in FIG. 2. Also, since temperature of thegases is much higher, the total purge time is greatly reduced. In thisregard, the total flow rate of the hot purged gases at the air intakesystem should be carefully controlled so that the composite temperatureof the inlet air is not too hot for efficient utilization of theresulting air fuel mixture within the combustion chamber of the engine.

FIG. 7 illustrates yet another mode for desorbing the elution and vaporadsorption zones of the cannister assembly of FIGS. 2 and 4. Inaccordance with the illustrated embodiment, engine air is heated bypassing the air adjacent to exhaust manifold 130 and thence through thecannister assembly where desorption occurs.

In more detail, the exhaust manifold 130 is provided with an exteriorhood 131 having lower skirts 132 which snuggly fit adjacent to theexhaust manifold, yet are open to incoming air. A central register 133is also provided with a nozzle 134. Nozzle 134 in turn is attached byflexible conduit 135 connected at a port 136, say at the air intake line13a of the air intake system of the embodiment of FIG. 2. At the airintake line 13a, a solenoid operator 137 is positioned so that damper138 is in register with port 136. Opening the damper 138 allows warmedengine air to enter the cannister assembly (not shown).

FIGS. 8 and 9 depict the operation of the conduit and valve network 26in detail. In FIG. 8, the inlet and outlet cold start valves 26a and 26bare seen to be in a relaxed state to allow utilization of the full-rangefuel. In FIG. 9, the evaporative control valve 26c is in position tocarry out the vapor adsorption control function of the presentinvention. That is to say, the evaporative control valve 26c is in arelaxed state so that its exhaust port 140 and inlet port 141 is influid communication with the gas tank 23. When the engine is inaninactive state, and evaporation of the fuel occurs, the vapors passthrough the control valve 26c, and conduit 50 to the vapor adsorptionzone of the cannister assembly 28 of FIGS. 2 and 4. Adsorption of thevapor prevents its escape into the atmosphere.

While certain preferred embodiments of the invention have beenspecifically disclosed above, it should be understood that the inventionis not limited thereto as many variations will be readily apparent tothose skilled in the art and thus the invention is to be given thebroadest possible interpretation within the terms of the followingclaims.

I claim:

1. Apparatus for reducing exhaust and inoperative pollutants produced bya high speed injection system for a spark-ignition internal combustionengine of the type including a rotating shaft, an intake manifold, oneor more cylinders each having an injection valve responsive to a controlsignal for injecting and mixing a predetermined quantity of full-rangefuel with air to form a combustible mixture for delivery to saidcylinders of said engine, and computing means including synchronizationand condition means for controlling said injection valves throughgeneration of said control signals as a function of one or more engineoperating parameters, said synchronizing means being operativelyconnected to each of said injection valves for synchronizing operationthereof as a function of predetermined angular shaft position bygenerating a series of start signals for said injector valves, saidcondition means responsive to each of siid start signals as well as tosignals indicative of other operating parameters, for controlling theduration of energization of said injection valves, comprising:

i. a cannister assembly containing adsorbent material (a) capable ofselectively adsorbing high molecular weight constituents of saidfull-range fuel at cold start whilc eluting substantially unimpeded acold start fuel effluent composed essentially of only low molecularweight constituents as well as (b) capa ble of selectively absorbingvapor constituents of said full-range fuel during an inoperative stateof said engine,

tween said cannister assembly, said injector valves, said intakemanifold and a reservoir means for said full-range fuel for providingselective flow of said fuel including said cold start fuel between saidcannister assembly, said reservoir means and each of said injectorvalves, said network means including a first plurality of conduit andvalve means including first and second valve means controlling flowrelative to said cannister assembly so as to allow, (a) in a firstoperating state, flow of said full-range fuel from said reservoir meansto said cannister assembly and flow of said cold start fuel effluentfrom said cannister assembly to said each injector valve to provide forrapid starting of said engine without producing excessive exhaustpollutants and, (b) in a second operating state, full-range fuel to flowfrom said reservoir means to said each injector valve in sequencethereby bypassing said cannister assembly after said engine is in anormal running condition, said network means also including a secondplurality of conduit means including a third valve means operativelyconnected between said cannister assembly and said fuel reservoir meansfor selectively conveying vapor evaporative emissions of said fuelwithin said fuel reservoir to said cannister assembly, when said engineis in said inoperative state,

iii. control means operatively connected to said first, second and-thirdvalve means of said valve and conduit network for changing operationstates so as to direct fuel flow relative to said cannister assembly,said reservoir and injector valves as a function of one or more engineoperating parameters.

2. Apparatus of claim 1 in which said cannister assembly includes anelongated tubular means disposed within an enlarged shell housing toform a shell-andtube arrangement for conduction of tube-side andshell-side fluids in adjacent but independent flow relationship, saidtubular means including a central segment supporting a first bed ofadsorbent material forming an elution zone for eluting low molecularweight cold start fuel, and separate inlet and outlet means connected tosaid reservoir and said each injector valve respectively, through saidfirst and second valve means, so as to selectively deliver fuel to saideach injector valves as a function of a selected engine parameter, saidshell housing including a central portion forming a second bed ofadsorbent material open at one end to atmosphere surrounding said engineand at another end connected to an intake manifold so as to guide atleast a part of intake air adjacent to said each injector valve, and anentry vapor conduit means connected to said reservoir means through saidthird valve so as to allow selection vapor contact therebetween as afunction of a selected engine parameter indicative of the inoperativestate of said engine whereby evaporative emissions can be absorbedwithin said section adsorbent bed and do not escape into atmospheresurrounding said engine.

. valve and conduit network means attached be- I 3. Apparatus of claim2, in which said elongated tubular means includes a singular .tubularconduit arranged within a single tubular shell housing, said singletubular conduit arranged to rigidly support said first bed of adsorbentmaterial therein but having radially extending inlet and outlet conduitmeans in contact with first and second valve means respectivelyso as toallow only single pass flow of said full-range fuel relative to saidshell having housing during cold start of said engine.

4. Apparatus of claim 2 in which said tubular means is a multiplicity oftubular conduits each arranged parallel to each other within a singletubular shell housing, each conduit supporting a segment of said firstbed of adsorbent material but all terminating at central inlet andoutlet chambers in operative contact with said first and second valvemeans, whereby full-range fuel percolating therethrough during coldstarting of said engine is provided with a multiplicity of sinusoidalpaths within said single enlarged tubular shell housing.

5. Apparatus of claim 1 in which said adsorbent materials within saidfirst and second adsorbent beds are of different polarityclassification.

6. Apparatus of claim 5 in which said first adsorbent bed is formed of apolar adsorbent material while said second adsorbent bed is formed of anonpolar adsorbent material.

7. Apparatus of claim 2 in which said one end of said shell housing isconnected by air intake control means including conduit means, to asource of heated gas, so as to allow selective flow of said heated gasthrough said cannister assembly for purging both first and second bedsof adsorbed fuel constituents, said purged constituents from said firstand second beds being carried into and consumed within said cylinders ofsaid engine during normal running operation.

8. Apparatus of claim 2 inwhich said engine includes an air intakesystem comprising an air cleaner assembly having an air intake line andan air filter,said air intake line includingsupport means for rigidlysupporting said cannister assembly in flow relationship with an intakemanifold of said engine adjacent tov said injector valves.

1. Apparatus for reducing exhaust and inoperative pollutants produced bya high speed injection system for a spark-ignition internal combustionengine of the type including a rotating shaft, an intake manifold, oneor more cylinders each having an injection valve responsive to a controlsignal for injecting and mixing a predetermined quantity of full-rangefuel with air to form a combustible mixture for delivery to saidcylinders of said engine, and computing means including synchronizationand condition means for controlling said injection valves throughgeneration of said control signals as a function of one or more engineoperating parameters, said synchronizing means being operativelyconnected to each of said injection valves for synchronizing operationthereof as a function of predetermined angular shaft position bygenerating a series of start signals for said injector valves, saidcondition means responsive to each of siid start signals as well as tosignals indicative of other operating parameters, for controlling theduration of energization of said injection valves, comprising: i. acannister assembly containing adsorbent material (a) capable ofselectively adsorbing high molecular weight constituents of saidfull-range fuel at cold start while eluting substantially unimpeded acold start fuel effluent composed essentially of only low molecularweight constituents as well as (b) capable of selectively absorbingvapor constituents of said full-range fuel during an inoperative stateof said engine, ii. valve and conduit network means attached betweensaid cannister assembly, said injector valves, said intake manifold anda reservoir means for said full-range fuel for providing selective flowof said fuel including said cold start fuel between said cannisterassembly, said reservoir means and each of said injector valves, saidnetwork means including a first plurality of conduit and valve meansincluding first and second valve means controlling flow relative to saidcannister assembly so as to allow, (a) in a first operating state, flowof said full-range fuel from said reservoir means to said cannisterassembly and flow of said cold start fuel effluent from said cannisterassembly to said each injector valve to provide for rapid starting ofsaid engine without producing excessive exhaust pollutants and, (b) in asecond operating state, full-range fuel to flow from said reservoirmeans to said each injector valve in sequence thereby bypassing saidcannister assembly after said eNgine is in a normal running condition,said network means also including a second plurality of conduit meansincluding a third valve means operatively connected between saidcannister assembly and said fuel reservoir means for selectivelyconveying vapor evaporative emissions of said fuel within said fuelreservoir to said cannister assembly, when said engine is in saidinoperative state, iii. control means operatively connected to saidfirst, second and third valve means of said valve and conduit networkfor changing operation states so as to direct fuel flow relative to saidcannister assembly, said reservoir and injector valves as a function ofone or more engine operating parameters.
 2. Apparatus of claim 1 inwhich said cannister assembly includes an elongated tubular meansdisposed within an enlarged shell housing to form a shell-and-tubearrangement for conduction of tube-side and shell-side fluids inadjacent but independent flow relationship, said tubular means includinga central segment supporting a first bed of adsorbent material formingan elution zone for eluting low molecular weight cold start fuel, andseparate inlet and outlet means connected to said reservoir and saideach injector valve respectively, through said first and second valvemeans, so as to selectively deliver fuel to said each injector valves asa function of a selected engine parameter, said shell housing includinga central portion forming a second bed of adsorbent material open at oneend to atmosphere surrounding said engine and at another end connectedto an intake manifold so as to guide at least a part of intake airadjacent to said each injector valve, and an entry vapor conduit meansconnected to said reservoir means through said third valve so as toallow selection vapor contact therebetween as a function of a selectedengine parameter indicative of the inoperative state of said enginewhereby evaporative emissions can be absorbed within said sectionadsorbent bed and do not escape into atmosphere surrounding said engine.3. Apparatus of claim 2, in which said elongated tubular means includesa singular tubular conduit arranged within a single tubular shellhousing, said single tubular conduit arranged to rigidly support saidfirst bed of adsorbent material therein but having radially extendinginlet and outlet conduit means in contact with first and second valvemeans respectively so as to allow only single pass flow of saidfull-range fuel relative to said shell having housing during cold startof said engine.
 4. Apparatus of claim 2 in which said tubular means is amultiplicity of tubular conduits each arranged parallel to each otherwithin a single tubular shell housing, each conduit supporting a segmentof said first bed of adsorbent material but all terminating at centralinlet and outlet chambers in operative contact with said first andsecond valve means, whereby full-range fuel percolating therethroughduring cold starting of said engine is provided with a multiplicity ofsinusoidal paths within said single enlarged tubular shell housing. 5.Apparatus of claim 1 in which said adsorbent materials within said firstand second adsorbent beds are of different polarity classification. 6.Apparatus of claim 5 in which said first adsorbent bed is formed of apolar adsorbent material while said second adsorbent bed is formed of anonpolar adsorbent material.
 7. Apparatus of claim 2 in which said oneend of said shell housing is connected by air intake control meansincluding conduit means, to a source of heated gas, so as to allowselective flow of said heated gas through said cannister assembly forpurging both first and second beds of adsorbed fuel constituents, saidpurged constituents from said first and second beds being carried intoand consumed within said cylinders of said engine during normal runningoperation.
 8. Apparatus of claim 2 in which said engine includes an airintake system comprising an air cleaner assembly having an air intakeline and an air filter, said air intake line including support means forrigidly supporting said cannister assembly in flow relationship with anintake manifold of said engine adjacent to said injector valves.